The upgrade items themselves are BoE and can be traded or sold on the Auction House

They can be used by anyone (not just engineers)

Using an upgrade item on gear will NOT bind it to you if it is not already bound to you

The upgrade item will NOT change the combination or proportion of stats on the item (e.g. if non-upgraded version has versatility and haste, the upgraded item will also have versatility and haste, just more of each stat)

These items can be used on gear that is already equipped

These upgrade items are exclusively crafted by Engineers - you cannot craft them as a non-Engineer, even with the Engineering Works building in your garrison

Plan : Réducteur de bulles bi-directionnel, sold by the Ore Trader visitor in your garrison - Alexi Hackercam (A) or Trixxy Volt (H). Note that you have a 1/5 chance of having a tradeskill vendor in your garrison every day, and there is a set rotation of tradeskill visitors from day to day (between herb, fur, leather, ore and dust). The easiest way to find this vendor is to use the Group Finder under Custom Premade Groups on the day that the Ore Trader is active.

Schéma : Lunettes anti-infrableu, sold by the Ore Trader visitor in your garrison - Alexi Hackercam (A) or Trixxy Volt (H). Note that you have a 1/5 chance of having a tradeskill vendor in your garrison every day, and there is a set rotation of tradeskill visitors from day to day (between herb, fur, leather, ore and dust). The easiest way to find this vendor is to use the Group Finder under Custom Premade Groups on the day that the Ore Trader is active.